The Acute Cardiovascular Effects of Nicotine in E-cigarettes (ACE) Study

Inclusion Criteria: 1. Participant will be currently healthy individuals, between 18 and 40 years of age. 2. E-Cigarette users using E-Cigarette for at least 1 month and smoke ≤ 1 tobacco cigarette / day; non-smokers who used less than 100 tobacco cigarettes in their lifetime and are not active nicotine/tobacco or related product users 3. Participants willing to abstain from vaping, smoking and tobacco for 12 hours prior to study. 4. Do not meet any of the Exclusion criteria. Exclusion Criteria: 1. Unwilling or unable to provide informed consent. 2. Participant that have: Diabetes, Hypertension HIV, hepatitis, liver disease (including fatty liver), anemia, unhealed wounds, active infection, febrile, anemia, organ transplant, renal replacement therapy, kidney disease or insufficiency, dialysis, active cancer of any type, and untreated thyroid disease, major injury or trauma. 3. Body weight less than 100 pounds or BMI \>40. 4. Participants that are taking the following medications: estrogen, testosterone, anti TNF agents, cyclophosphamide, ketoconazole, methoxsalen, pilocarpine, Isoniazid, rifampicin certain biologics, or Procrit 5. Participants that are currently using nicotine patches, nicotine gum or any form of nicotine-containing cessation device 6. Pregnant or lactating women. 7. Prisoners and other vulnerable populations. 8. Anyone that PI thinks is unsafe to participate in the study.